STUDY I: Classification and Assessment of Suicidal Behaviors. In order to test and refine a schema for the classification of suicidal behaviors we evaluated and are following up 730 hospitalized suicidal patients. We developed instruments that assess suicidal intent, medical lethality, extent of suicidal ideation, and hopelessness. For the renewal period, we plan to extend the follow-up on our patients in order to get a more accurate mortality rate and determine the predictive validity of our instruments. We also plan to identify the chronic suicidal patient and trace the natural histories of depressed and suicidal individuals. STUDY II: A Comparison of the Effects of Cognitive/Behaviorla Therapy, Amitriptyline, and Combined Therapy on Depressed, Suicidal Outpatients. In order to delineate therapeutic approaches with optimum short-term and long-term benefits in the treatment of depression, we will compare the efficacy of cognitive/behavior therapy versus amitriptyline. Through the application of specific, well-defined therapeutic techniques our treatment package focuses on changing the negative cognitive factors central in depression. Reducing the intensity of suicidal wishes will be a specific therapeutic target. We propose to investigate this therapy's efficacy versus chemotherapy, in terms of: 1) the relief of overall depressive and target symptoms, 2) the comparative short-range and long-range effects, 3) identification of patients differentially responsive to one form of therapy, and 4) the effects of combined psychotherapy and pharmacotherapy. Ninety depressed outpatients will be randomly assigned to three groups: 1) cognitive/behavioral therapy, 2) amitriptyline, and 3) combination therapy and amitriptyline. Treatment will be provided for 12 weeks, during which the patients will be systematically evaluated. Monthly follow-up evaluations will continue subsequent to treatment termination. Our use of a wide variety of measures will enable us to also assess the long-term effects of the various treatment modalities.